CCK select widget with CCK Content Taxonomy

Hi--
First up: love this module! Thanks for the contribution.

I have two Content Taxonomy fields within a form. Each Content Taxonomy field displays a select list generated by a list of taxonomy terms. E.G:
field_good is a drop-down with values Yes and No (referenced from a vocabulary containing these terms)
field_how_good is a drop-down with 4 values (referenced from a vocabulary containing these terms)

As has been addressed before I need to validate input based upon another field. In my case:

if ($form_state['values']['field_good'] == 'Yes') {
   return ($value != '');
}
return TRUE;

For the life of me this code isnt working. It's like the value in $form_state['values']['field_good'] isnt even there. With the web developer module in firefox with I can "view form information" to inspect the values of each form field; field_good reports no value.

Any ideas? Im hoping this isnt one of those "#after_build" scenarios ;P

thanks much and kind regards,
pp